NUCLEO491RE I2C COMMUNICATION WITH TCA9537

[ishu]

I am using nucleo491re MCU  to communicate with tca9537 GPIO-Expander . I want to use GPIO  for on/off  in tca9537 based on i2c . IN tca9537 I have four resister 1. Input(read) address( 0x01) 2.output (read/write) address(0x02) 3.polarity address( 0x03) .4.configuration address(0x04). and slave address (0x49).

For changing all pins to output mode .

HAL_I2C_Mem_Write(&hi2c, (slave address<<1), configuration address , 1,(uint8_t*) 0xF0, 1, I2C_TIMEOUT);

FOR making pins to high state .

HAL_I2C_Mem_Write(&hi2c, (slave address<<1), output , 1,(uint8_t*) 0xFF, 1, I2C_TIMEOUT);

 

I am getting only slave address on SDA LINE and IO pins not showing anything not high and not law

anyone tell me how to use GPIO-Expander pins for on/off purpose.

 

[Foued_KH]

Hello @ishu , 

Could you please share a screenshot from the analyzer?

Foued 

[ishu]

SDA-YELLOW ,SCL-GREEN,PIN P0 =RED

[TDK]

> (uint8_t*) 0xF0

This doesn't do what you think it does. Do this instead:

uint8_t data = 0xF0;
HAL_I2C_Mem_Write(&hi2c, (slave address<<1), configuration address, 1, &data, 1, I2C_TIMEOUT);

 

[Foued_KH]

Hi @ishu ,

Do this instead: 

 

#define slave address 0x49 << 1
uint8_t data = 0xF0;
HAL_I2C_Mem_Write(&hi2c, slave address, configuration address , 1,&data , 1, I2C_TIMEOUT);

 

Foued

[David Littell]

Verify the TCA register addresses your using relative to Table 8-2.